Exploring Applicable Scenarios and Boundary of MAC Protocols: A MAC Performance Analysis Framework for Underwater Acoustic Networks

Medium Access Control (MAC) protocols are critical for scheduling resources to access multiple users without collisions in Underwater Acoustic Networks (UANs). Due to harsh marine environments and limited communication resources, UANs lack a standard MAC protocol to adapt to various scenarios. The specific UAN scenario suffers from how to analyze multiple basic MAC protocols' performance boundaries and modify the most potential one. A practical solution is to evaluate MAC protocols' performance by modeling data loss (collisions and packet errors) and service time. However, existing models provide inaccurate performance results, since they ignore the effects of unique UANs' characteristics and MAC protocol diversity on data loss and service time. In this paper, we propose a MAC Performance Analysis Framework (MPAF) for UANs to consider both unique UANs' characteristics and MAC protocols' diversity. We design Successful Transmission Probability (STP) model and Packet Service Time (PST) model in MPAF to estimate nodal throughput, delay, and energy consumption. STP model analyzes data loss types of different MAC protocols by considering long propagation delay, half-duplex communication, and random backoff to achieve a superior STP result from a view of real underwater communication conditions. Based on STP model, we employ Markov chain to deduce the retransmission number in PST model. In this way, MPAF ensures effectiveness and applicability in real-ocean environments. Extensive simulation results show that MPAF can accurately evaluate different MAC protocols' performance boundaries, select the most appropriate basic protocol, and provide modified suggestions for a specific UAN scenario.